RU2356675C1 - Manufacturing method of steel profile shell - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to metal deformation process field, particularly to manufacturing of steel profile shell. Blank is installed and fixed on profile mandrel, it is implemented induction and gas-flame heating with control and regulation of temperature and effect the blank by deformation tool. Additionally after fixing of blank on mandrel it is installed inductor from the fixation side, coaxial with blank into run position and blank is preheated by induction method up to the temperature of 950-1250°C. Then inductor is returned into beginning position and it is implemented for one or several passage forming of profile surface of blank by rollers with reverse warped of work surface profile and displaced to each other. Keeping of defined temperature conditions is implemented by gas-flame heating by means of burner, installed in top supports of stand over mandrel with controller and regulation of temperature by pyrometre, installed on bottom supports under the mandrel. After what it is implemented forming of unshaped surface of cold blank by rollers, allowing tapered working surface with different angle of slopes forming and displace to each other.

EFFECT: it is increased geometrics accuracy and process productivity.

5 cl, 8 dwg, 1 ex, 1 tbl

Description

The invention relates to the field of metal forming, in particular to the manufacture of parts with a profile in the form of a cylinder, cone and a second-order curve of high-carbon steel (steel 35, 40, etc.), for example, gas cylinders, liners and fire extinguishers.

The most important problem in the production of shells with sections of a cylindrical, conical and curvilinear profile from hard-to-deform high-carbon and refractory steels is the fundamental possibility of their manufacture by rotational drawing with high accuracy, surface quality and high performance with heating and in cold condition.

Currently, there are many ways to rotary hoods: single-junction and multi-jaw rotary hoods, rotary crimping, rotary hoods and others, in the cold state and with heating.

In the book (by NI Mogilny, “Rotational extraction of shell parts on machines”; Moscow, Mechanical Engineering, 1983), various methods for producing shell parts by rotational hood are described.

A disadvantage of the known schemes in relation to the problem of obtaining all-metal shells of large length and significant wall thickness from hard-to-deform (high-carbon, alloy and refractory) steels is the impossibility of obtaining such parts according to known schemes due to the complexity of their shape, high strength and low ductility of the material.

The closest in technical essence and the achieved technical result is a method of manufacturing parts with gas-flame heating during the rotational extraction of conical and curvilinear shells of carbon and stainless steel and refractory metals (see the book "Pressure work and rotational extrusion", M. A. Gredor, Moscow, Engineering, 1971, pp. 68-71, Fig. 42, 44, 45), adopted by the authors as a prototype, in which the preform is heated in front of the deformation zone with a temperature control and regulation system, moreover, gas mount and a pyrometer ku fixedly on the rear side of the machine with a rotary draw shells conical or curved shape, and a front side of the machine has a support with a wine-press roller. The gas burner and pyrometer are not connected to the caliper.

The flat workpiece is fixed on the mandrel with a clamp, turn on the spindle with the mandrel and the workpiece, supply and ignition of gas in the burner.

Then carry out a radial and axial feed of the caliper with a roller.

As can be seen from this technical solution, the rotational drawing process is carried out with gas-flame heating on mandrels of a conical or curvilinear shape from a flat billet.

The reasons that impede the achievement of the specified technical result when using the known method adopted by the authors for the prototype is the impossibility of its use in the manufacture of profile shells of great length and considerable thickness from the tube stock, since when forming long and thick blanks with one roller with a stationary burner and pyrometer it is impossible to heat a workpiece with a gas flame along its entire length and thickness.

Preliminary heating of the workpiece by the induction method is not used in this technical solution.

Thus, the objective of this technical solution was to create a method of manufacturing parts with gas-flame heating during the rotational drawing of shells of a small length, conical or curvilinear, from flat billets, without ensuring the shape of pipe billets of large length and thickness.

Common features with the method proposed by the authors is the installation and fixing of the workpiece on a profile mandrel, gas-flame heating of the workpiece with temperature control and regulation, and the impact on the workpiece with a deforming tool.

In contrast to the prototype, in the method of manufacturing steel profile shells proposed by the authors, after the workpiece is fixed on the mandrel, the inductor is mounted on the mounting side, coaxially with the workpiece in the working position and the workpiece is preheated by the induction method to a temperature of 950-1250 ° C, then the inductor is returned to its original position and carry out in one or more passes the shaping of the profiled surface of the workpiece by rollers with a variable curvature of the profile of the working surface and offset from each other, while maintaining the specified temperature is carried out by gas-flame heating by means of burners installed on the upper calipers of the machine above the mandrel with temperature control and pyrometer installed on the lower calipers under the mandrel, after which the shape of the blank surface of the workpiece is cold formed by rollers having conical working surfaces with different angles of inclination of generators and offset from each other.

In special cases, that is, in specific forms of execution, the invention is characterized by the following features:

- the inductor is installed in the initial position at a distance of more than one diameter of the workpiece from the beginning of the mandrel profile, and in the working position with overlapping the end of the workpiece at a distance of not less than 1.5 the wall thickness of the workpiece, while the gap between the inner surface of the inductor and the workpiece is chosen equal to 1, 0-3.0 thickness of the workpiece;

- control of the temperature of flame heating is carried out using a pyrometer installed in the same plane with the axis of the workpiece and the temperature control zone, which is set by pointing the laser marker of the pyrometer on the surface of the workpiece between the deformation zones at an equal distance from them;

- forming the blank profile with gas-heated heating is carried out by rollers with a working surface profile in the form of an involute with a radius of the initial circle of 5-8 wall thicknesses of the workpiece and a length equal to the height of the working surface profile of the roller, and the axial displacement of the rollers is up to two wall thicknesses of the workpiece when the gap between the top of the profile and the mandrel of the first in the direction of the axial feed of the roller is 1.1-1.5 times the size of the gap of the second roller;

- forming the non-profiled surface of the workpiece in the cold state is carried out by rollers, the first of which is made with an angle of inclination of the generatrix of the working surface, 1.5-2.5 less than the angle of inclination of the generatrix of the subsequent rollers, and displaced in the axial direction relative to them by up to 0.7 the wall thickness of the workpiece, with the gap between the top of the profile of the first roller and the mandrel, a larger gap between the tops of the profile of the subsequent rollers and the mandrel by 3-7%.

It is this that allows us to conclude that there is a causal relationship between the totality of the essential features of the claimed technical solution and the achieved technical result.

The indicated features, distinctive from the prototype and to which the requested scope of legal protection applies, are sufficient in all cases.

The objective of the invention is to enable the formation of steel profile shells from tubular billets of large length and thickness with induction and flame heating, and subsequent cold forming with high stability of the forming process, high quality of the machined surface, accuracy of geometric parameters and high productivity.

The specified technical result during the implementation of the invention is achieved by the fact that in the known method, the workpiece is mounted and fixed on a profile mandrel, the workpiece is gas-flame heated with temperature control and regulation and the workpiece is subjected to a deforming tool, the peculiarity is that after fixing the workpiece on the mandrel, an inductor is installed from the fastening side coaxially with the workpiece in the working position and pre-heat the workpiece by induction to temperatures 950-1250 ° C, then return the inductor to its original position and carry out in one or several passes the shape change of the profiled workpiece with rollers with a variable curvature of the working surface and offset between them, while maintaining a given temperature regime is carried out by flame heating using burners installed on the upper calipers of the machine above the mandrel with temperature control and regulation with a pyrometer mounted on the lower calipers under the mandrel, after which the form changing the non-profiled surface of the workpiece in the cold state by rollers having conical working surfaces with different angles of inclination of the generators and offset from each other.

The new set of operations, as well as the presence of relations between them, allow due to:

- pre-heating the workpiece by the induction method to a temperature of 950-1250 ° C to reduce the heating time and gas flow during subsequent gas-flame heating in the process of forming the profiled surface;

- setting the inductor in the working position coaxially with the workpiece from the side of its attachment to the mandrel and the machine spindle and returning the inductor to its original position after pre-heating the workpiece, reduce the manufacturing time of the part, since with this technological method the workpiece surface treatment area for forming with gas-flame heating is freed up and subsequent removal and unloading;

- shaping the profiled surface of the workpiece with rollers with a variable curvature of the profile of the working surface to ensure smooth growth of deformation along streamlines (metal flow) in the deformation centers;

- shaping the profiled surface of the workpiece with rollers shifted between each other, to divide the deformation between the rollers with equal radial forces and thereby increase the stability of the forming process, reduce the number of passes and the complexity of manufacturing with high quality of the machined surface and the accuracy of geometric parameters;

- installation of gas burners on the upper (transverse) calipers above the mandrel, and a pyrometer for monitoring and adjusting the temperature of gas-flame heating on the lower (longitudinal) calipers of the machine under the mandrel - to ensure uniform heating and maintaining the specified temperature regime at all passes of forming the profiled surface of the workpieces, due to the fact that when moving the upper calipers and rollers according to the CNC program, gas burners move according to the same program, ensuring uniform heating of the workpieces along the entire length shaping, and the accuracy of measurements and adjusting the heating temperature of the workpiece is ensured by the fact that with this arrangement the pyrometer is protected from glare of the burner flame and ingress of slag and combustion products;

- cold forming of the non-profiled surface of the workpiece by rollers having conical working surfaces with different angles of inclination of the generators and offset from each other, - to increase the stability of the forming process as a result of the separation of deformation between the rollers with equal radial forces, and also to improve the quality of the processed surface and the accuracy of geometric parameters . Signs characterizing the invention in specific forms of execution, allow, in particular, due to:

- installation of the inductor in the initial position at a distance of more than one diameter of the workpiece from the beginning of the mandrel profile, corresponding to the beginning of the profiled surface of the workpiece, - to protect the inductor from a gas flame during subsequent gas-flame heating;

- installation of the inductor in the working position with overlapping the end face of the workpiece at a distance of at least 1.5 wall thickness of the workpiece - to ensure uniform heating of the workpiece over the entire machined profiled surface, since when closing the end of the workpiece by less than 1.5 wall thickness, the end face of the workpiece does not warm up ;

- selection of the gap between the inner surface of the inductor and the workpiece equal to 1.0-3.0 wall thicknesses, to ensure safe operation of the inductor at a high heating speed of the workpiece and to reduce the heating time, while when choosing the gap in the range of less than 1.5 wall thickness overheating of the inductor occurs, and with more than 3 wall thicknesses, the time for heating the workpiece to a temperature of 950-1250 ° C increases;

- installing the pyrometer in the same plane with the axis of the workpiece and the temperature control zone, which is set by pointing the laser marker of the pyrometer on the surface of the heated workpiece between the deformation zones at an equal distance from them, - to ensure high accuracy of measurements and adjusting the temperature of the metal of the workpiece, since in this case the temperature control zone does not get the flame of a gas burner;

- shaping the workpiece profile with gas-flame heating by rollers with a working surface profile in the form of an involute with a radius of the initial circle of 5-8 wall thicknesses of the workpiece and a length equal to the height of the working surface profile of the roller, to ensure the optimal deformation, since with the radius of the initial circle less than 5 wall thicknesses and an involute length shorter than the profile height, the smoothness of deformation growth in the deformation zones is violated with a deterioration in the quality of the treated surface in the form of sagging, and with a radius value of more than 8 wall thicknesses and an involute length greater than the profile height of the working surface of the roller, the radial forces on the rollers sharply increase, the stability of the forming process decreases, corrugations, cracks form;

- forming a profile of a workpiece with gas-flame heating with axial displacement of the rollers up to two wall thicknesses with a gap between the top of the profile and the mandrel of the first in the direction of the axial feed of the roller, 1.1-1.5 times the size of the gap of the second roller, to ensure optimal separation of deformation between the rollers with equal radial forces, since with an axial displacement of more than two wall thicknesses and a clearance of more than 1.5 times, the radial load on the first roller increases, the runout of the mandrel increases, and, in result ltate reduced deformation resistance gofroobrazovaniem process followed, but with a small axial displacement and separation gaps malootlichimyh deformation does not occur, the stability of the forming process is reduced, the danger increases gofroobrazovaniya;

- shaping the non-profiled surface of the workpiece in the cold state with rollers, the first of which is made with an angle of inclination of the generatrix of the working surface, 1.5-2.5 less than the angle of inclination of the generatrix of the subsequent rollers and offset in the axial direction relative to them by up to 0.7 wall thickness workpieces, with a gap between the top of the profile of the first roller and the mandrel, a larger gap between the tops of the profile of the subsequent rollers and the mandrel by 3-7%, with equal radial forces - to increase the stability of the process changes and accuracy of the resulting shells as a result of the separation of deformation between the first roller in the direction of axial feed and subsequent rollers, which is optimal for steel shells, while at an angle of inclination of the generatrix of the working surface of the first roller beyond these limits (less than 1.5-2 5 times), and with an axial displacement of more than 0.7 wall thickness, as well as with the ratio of the gaps between the top of the profile of the first roller and the mandrel, and the vertices of the profiles of the subsequent rollers and the mandrel is beyond the specified limits ( olee 3-7%) there is a difference of radial forces on the rollers, resulting in a loss of stability of deformation process with the appearance of cracks and corrugations.

Signs that distinguish the proposed technical solution from the prototype are not identified in other technical solutions and are not known from the prior art in the process of conducting patent research, which allows us to conclude that the invention meets the criterion of "novelty."

Examining the prior art during a patent search on all types of information available in the countries of the former USSR and foreign countries, it was found that the proposed technical solution does not explicitly follow from the prior art, therefore we can conclude that the criterion of "inventive step" .

The essence of the invention lies in the fact that in the method of manufacturing steel profile shells, in which the workpiece is mounted and fixed on the profile mandrel, gas-flame heating is carried out with temperature control and regulation and the workpiece is subjected to a deforming tool, in contrast to the prototype, according to the invention, after fixing the workpiece on the mandrel, the inductor is mounted on the fastening side, coaxially with the workpiece, in the working position and the workpiece is preheated by induction to the temperature Grades 950-1250 ° C, then the inductor is returned to its original position and, in one or several passes, the non-profiled surface of the workpiece is changed by rollers with a variable curvature of the working surface profile and offset from each other.

In the particular case, that is, in specific forms of execution, the invention is characterized by the following features:

- in the initial position, the inductor is installed at a distance of more than one diameter of the workpiece from the beginning of the mandrel profile, and in the working position with overlapping the end of the workpiece at a distance of not less than 1.5 thickness of the workpiece, the gap between the inner surface of the inductor and the workpiece is chosen equal to 1.0 -3.0 wall thickness of the workpiece;

- control of the temperature of flame heating is carried out using a pyrometer installed in the same plane with the axis of the workpiece and the temperature control zone, which is set by pointing the laser marker of the pyrometer on the surface of the workpiece between the deformation zones at an equal distance from them;

- forming the blank profile with gas-heated heating is carried out by rollers with a working surface profile in the form of an involute with a radius of the initial circle of 5-8 thicknesses of the workpiece wall and a length equal to the height of the working surface profile of the roller, and the axial displacement of the rollers is up to two thicknesses of the workpiece at the gap between the top of the profile and the mandrel of the first, in the direction of the axial feed, 1.1-1.5 times larger than the gap of the second roller;

- forming the non-profiled surface of the workpiece in the cold state is carried out by rollers, the first of which is made with an angle of inclination of the generatrix of the working surface, 1.5-2.5 less than the angle of inclination of the generatrix of the subsequent rollers and offset in the axial direction relative to them by up to 0.7 thickness walls, with the gap between the top of the profile of the first roller and the mandrel, the gap between the vertices of the profile of the subsequent rollers and the mandrel is 3-7%.

The essence of the proposed image is illustrated by drawings, where in the form of diagrams shows the implementation of the method:

- figure 1 - the process of preliminary induction heating of the workpieces with the installation of the inductor in the initial and operating position;

- figure 2, 3 - shaping the profiled surface of the workpiece with flame heating;

- figure 4 - shaping the profiled surface of the workpiece, a plan view;

- in Fig.5, 6, respectively, the axial section and the plan view of the deformation zones during the shaping of the profiled surface of the workpiece by rollers with an involute working surface profile;

- Fig.7 - shaping the non-profiled surface of the workpiece in a cold state, a plan view;

- Fig. 8 - deformation zones during the shaping of the non-profiled surface of the workpiece, axial section.

Figure 1 shows a tube billet 1, with a diameter of D ₀ mm and a thickness of t ₀ mm, mounted on a profile mandrel 2, in the process of preliminary induction heating with high-frequency currents by inductor 3. After heating the billet over

L _heat. to a temperature of 950-1250 ° C, the inductor 3 is returned to its original position at a distance (L ex _. ≥1D ₀ ) of more than one diameter of the workpiece. The inductor 3 is installed on the mounting side of the workpiece 1 at the machine spindle coaxially with the workpiece in the working position above the profile surface of the mandrel L _prof. with overlapping the end face of the workpiece at a distance a (mm) of at least 1.5 thickness of the workpiece (a≥1.5 t ₀ ), and the gap between the inner surface of the inductor and the workpiece b (mm) is chosen equal to 1.0-3.0 wall thickness (b = (1,0 ÷ 3,0) t ₀ ). The length of the inductor L _ind. set taking into account the amount of overlap (L _ind. = L _heat. + 2A).

Forming the profiled surface of the workpiece 1 (figure 2, 3, 4) in the profile area L _prof. mandrels 2 are carried out by rollers 4 and 5 while maintaining the temperature regime by gas-flame heating by means of burners 6 mounted on the upper (transverse) calipers 10 of the machine above the mandrel.

The inductor 3 (figure 2) when forming the profiled surface is taken to its original position at a distance L _ref. (mm).

Monitoring and temperature control during gas-flame heating is carried out by a pyrometer 7 mounted on the lower calipers 11 of the machine under the mandrel 2 (Fig. 2, 3, 4) in the same plane (section A-A, Fig. 2, 3) with the axis of the workpiece 2 and the zone temperature control 9 (Fig.2, 3, 4), which is set by pointing the laser marker 8 of the pyrometer 7 on the surface of the workpiece 2 between the deformation zones of the rollers 4 and 5 at an equal distance from them equal to D _1/2 (mm), where D ₁ - the current diameter of the profiled surface of the workpiece (figure 2, 4).

Forming the profile of the workpiece 1 with flame heating is carried out by rollers 4 and 5 (Fig. 5) with the profile of the working surface in the form of an involute (O ₁ -a) with an initial radius r ₀ (mm) of (5 ÷ 8) t ₀ (mm) , where t ₀ - wall thickness of the original billet, and a length of In _ev. (mm) equal to the height of the profile of the working surface of the roller H _prof. (mm). Point b with coordinates x, y and angles α and θ forms an involute curve O ₁ -a when rolling around the straight line AA along a circle with a radius of the initial circle r ₀ .

The rollers 4 and 5 are offset from each other in the axial direction by a value of c (mm), which is up to two thicknesses of the wall of the workpiece (c≤2 t ₀ ) when the value between the top of the profile and the mandrel of the first in the axial direction F of the roller 4 Δ ₁ (mm) (figure 5), 1.1-1.5 times the magnitude of the gap of the second roller 5, that is

Δ ₁ = (1.1-1.5) Δ ₂ .

The area of the deformation zones of the rollers 4 and 5 (Fig.6) are equal (s ₄ = s ₅ ). C (mm) is the axial displacement of the rollers, n is the direction of rotation of the rollers (figure 5, 6). The profiles of the rollers 4 and 5 (Fig. 5) are conditionally aligned in one axial plane, t is the current wall thickness of the shell on the profiled surface (Fig. 5).

Forming the non-profiled surface of the workpiece in the cold state (Fig.7, 8) is carried out by the rollers 1, 2, 3, and the profiles of the rollers 2 and 3 are conditionally aligned and located in the same axial plane with the profile of the roller 1. The first in the direction of the axial feed F roller 1 is made with the angle of inclination of the generatrix of the working surface α ₁ , 1.5-2.5 less than the angle of inclination α ₂ , forming the subsequent rollers 2 and 3, that is, α ₂ = α ₃ = (1,5 ÷ 2,5) α ₁ , and offset relative to the rollers 2 and 3 in the direction of the axial feed F by a value of s (mm) to 0.7 of the wall thickness of the workpiece t ₀ , that is, c≤0.7 t ₀ ( mm), and the gap Δ ₁ (mm) between the top of the profile of the first roller 1 and the mandrel 4 is greater than the gap Δ ₂ (mm) between the vertices of the profile of the subsequent rollers 2 and 3 and the mandrel is (3-7)%, i.e.

Δ ₁ = (1.03-1.07) Δ ₂ (mm).

The above method of manufacturing profile shells is as follows.

After fixing the workpiece 1 on the profile mandrel 2, the inductor 3 is installed from the side of the workpiece mounting to the mandrel coaxially with the workpiece in the working position (Fig. 1) and the workpiece is preheated by the induction method to a temperature of 950-1250 ° C, then the inductor is returned to its original position to the side fastening the workpiece to the mandrel and carry out in one or more passes the shape change of the profiled surface of the workpiece with a feed F (mm / min) and spindle speed n (r / min) (Figs. 2, 3, 4) with rollers 4 and 5 with variable curvature ofil of the working surface in the form of an involute and offset between each other (Figs. 5, 6), while maintaining a predetermined temperature regime is carried out by gas-flame heating by burners 6 installed on the upper calipers 10 of the machine above the mandrel with temperature control and regulation by pyrometer 7 installed on the lower calipers 11 machines (Fig.2, 3, 4).

Monitoring and temperature control during gas-flame heating with a pyrometer is carried out along the chain - pyrometer 7, machine control system, gas burners 6 (Figs. 2, 3, 4).

When increasing or decreasing the heating temperature of the metal of the workpiece for a given temperature interval, respectively, gas burners turn off or on.

Then, the forming of the non-profiled surface of the workpiece is performed, in the cold state, by rollers 1, 2, and 3 with different angles of inclination of the working surface forming and displaced in the axial direction with axial feed F (mm / min) and spindle speed n (r / min ) (Fig. 7, 8).

Example.

⌀200 × 16 mm pipes of steel 35 (40) are cut into billets, then the billets are subjected to turning on the outer and inner surfaces, maintaining the dimensions выдерж _int. = 201 mm, t ₀ = 10 mm. After that, the workpiece is installed and fixed on a profile mandrel ⌀ 200.6 mm with a radius of curvature of the profile R4375 mm and a small end diameter ⌀ 57.9 mm. Then, the inductor is installed on the side of the mounting of the workpiece to the mandrel, that is, on the spindle side, coaxially with the workpiece in the working position, so that the end face of the workpiece is blocked by the inductor at a distance of (Fig. 1) 20-30 mm, which is less than 1.5 wall thickness, less than 1.5 · t ₀ = 1.5 · 10 = 15 (mm), and <20 mm.

The gap between the inner surface of the inductor and the workpiece in mm (Fig. 1) is chosen equal to 15 mm, which is 1.5 the wall thickness of the workpiece (1.5t ₀ = 1.5 · 10 = 15 mm) and fits within 1.0- 3 wall thicknesses.

Then the workpiece is heated by induction in the area of L heat _. = 350 ± 5 mm (Fig. 1) in the following modes:

heating temperature 1250-1280 ° C;

generator current 130 A;

heating voltage 800 V;

heating time 6 minutes

Monitoring and regulation of the heating temperature is carried out by a thermoelectric converter TXA-0292, a temperature regulator "Thermodat" GOST 12997-84 and a time switch VL-47.

After that, the inductor is returned to its original position, maintaining the distance

L _ref. = 250 mm, more than one workpiece diameter ⌀ _zag. = 221 mm, that is, L _ref. = 250 mm> ⌀ _zag = 221 mm.

Then, the profiled surface of the workpiece 1 is shaped in 4 passes according to the CNC program of the machine with two rollers 4 and 5 while maintaining the temperature in the range of 950-1050 ° C by gas-flame heating (Figs. 2, 3 and 4) by means of two burners 6 mounted on the upper calipers 10 of the machine, above mandrel 2 with feed F = 350 (mm / min) with a spindle speed of n = 200 (rpm).

Temperature control and regulation is carried out in automatic mode by a pyrometer 7 of the company "Kelvin" KSDM 201119.005TU (Fig.2, 3 and 4) installed on the lower calipers 11 of the machine, under the mandrel 2.

Forming the profiled surface of the workpiece 1 on the mandrel 2 is carried out by rollers 4 and 5 with a variable curvature of the profile of the working surface in the form of an involute with the following parameters:

r ₀ = 70 mm is the radius of the initial circumference of the involute,

r ₀ = 7t ₀ = 7 × 10 = 70 (mm), which is in the range (5-8) t ₀ ,

In _ev. = 70 mm - the length of the involute,

In _ev. = H _prof. = 70 mm, where H _prof. - the height of the profile of the working surface of the rollers 4 and 5.

The coordinates of the points of the involute curve are calculated by the formulas:

X = ρsinθ,

Y = ρcosθ,

where ρ is the current radius (mm) of involute,

θ is the angle of inclination of the radius (figure 5),

which are determined by the formulas:

θ = tg α-α (°), ρ = t ₀ / cosα,

where α is the current angle angle between the initial circle

involutes and radius ρ, triangle obd (Fig. 5).

The calculation of the coordinates of the points of the involute is as follows.

The angle α ° is set, for example, every 3 °.

For each α ° value, θ ° and ρ (mm) are determined.

Then, for each value of α ° and ρ (mm), the X and Y coordinates are calculated.

The results of calculating the coordinates of the involute profile of the working surface of the rollers, at r ₀ = 70 mm and α ° every 3 ° are shown in table 1:

Table 1 α ° 3 ° 6 ° 9 ° 12 ° 15 ° 18 ° 21 ° 24 ° 27 ° 30 ° X mm 0.003 0,027 0.09 0.22 0.44 0.79 1.3 2,015 3.0 4.33 Y mm 70,095 70,385 70.87 71.56 72.47 73.59 74.96 76.59 78.5 80.7

α ° 33 ° 36 ° 39 ° 42 ° 45 ° 48 ° 51 ° 54 ° 57 ° X mm 6.11 8.47 11.57 15.66 21,035 28,125 37.5 49.94 66.45 Y mm 83.22 86.09 89.3 92.85 96.69 100.71 104.65 108,03 109.9

The preform with gas-flame heating is formed by rollers with an axial displacement of up to two wall thicknesses of up to 2 × 10 = 20 mm with a gap between the top of the profile and the mandrel of the first in the direction of axial feed, 1.1-1.5 times larger than the clearance of the second roller, when the gap value of the first roller 9, the gap of the second roller is 6.5 mm, that is, the gap of the first roller is 1.38 times greater than the gap of the second.

Then perform recrystallization softening annealing at a temperature of 630-650 ° C.

After that, the shape change of the non-profiled surface of the workpiece is performed, in the cold state it is carried out by rollers 1, 2 and 3 (Figs. 7, 8), the first of which is made with an inclination angle of the generatrix of the working surface α ₁ = 15 °, of 1.5-2.5 times smaller than the inclination angle of the generatrix of the subsequent rollers 2 and 3, α ₂ = α ₃ = 30 ° and is displaced in the axial direction relative to them by a value of c = 5 (mm) (Fig. 8) to 0.7 × 10 = 7 (mm) , when the gap between the top of the profile of the first roller and the mandrel is greater than the gap between the vertices of the profile of the subsequent rollers and the mandrel by (3-7)%, then e stand at Δ ₁ = 7.35 mm, Δ ₂ = Δ ₃ = 7.0 mm, Δ _{1 is} greater than Δ ₂ = Δ ₃ 5%.

Then perform degreasing, followed by annealing, which reduces the voltage at a temperature of 350-375 ° C.

After that, the shells are controlled by geometric parameters for compliance with the requirements of the shell drawing.

The implementation of the method of manufacturing steel profile shells in accordance with the invention, makes it possible to obtain parts of complex profile from hardly deformable and low plastic steels with high accuracy of the geometric shape and quality of the treated surface during induction and gas-flame heating, as well as in the cold state due to the high stability of the forming process, reduce the number of passes and reduce the complexity of manufacturing.

The invention can be used in the production of various steel profile shells from tube billets of large length and thickness with induction and flame heating, as well as with subsequent cold forming with high stability of the deformation process, high quality of the machined surface, accuracy of geometric parameters and high productivity.

The indicated positive effect is confirmed by testing prototypes of parts manufactured by this method.

Currently, technical documentation has been developed, tests have been carried out, serial production of products by the proposed method is planned.

Claims (5)

1. A method of manufacturing steel profile shells, including installing the workpiece and securing it to the profile mandrel, flame heating with temperature control and regulation, and the action of a deforming tool on the workpiece to shape it, characterized in that the workpiece is pre-heated by induction to a temperature of 950-1250 ° C, for which an inductor is used, which is installed in the working position from the side of the workpiece mounting coaxially with it after being fixed on the mandrel, and then the inductor is returned to a similar position, in one or more passes, the workpiece is shaped to produce a profiled surface with rollers with a variable curvature of the working surface and offset between them, while to maintain a given temperature regime, gas-flame heating is carried out by means of burners installed on the upper calipers of the machine above the mandrel, and control and temperature control is carried out by a pyrometer mounted on the lower calipers under the mandrel, after which they are shaped to give non-profiled workpiece surface in a cold state rollers having a conical working surfaces with different angles of inclination and forming the offset between them. 2. The method according to claim 1, characterized in that in the initial position the inductor is installed at a distance of more than one diameter of the workpiece from the beginning of the mandrel profile, and in the working position with overlapping the end face of the workpiece at a distance of not less than 1.5 of the wall thickness of the workpiece, the gap between the inner surface of the inductor and the workpiece is chosen equal to 1.0-3.0 wall thickness of the workpiece. 3. The method according to claim 1, characterized in that the pyrometer for monitoring the temperature of flame heating is installed in the same plane with the axis of the workpiece and the temperature control zone, which is set by pointing the laser marker of the pyrometer on the surface of the workpiece between the deformation zones at an equal distance from them. 4. The method according to claim 1, characterized in that when changing the profile of the workpiece with flame heating use rollers with a profile of the working surface in the form of an involute with a radius of the initial circumference of 5-8 thicknesses of the wall of the workpiece, and a length equal to the height of the profile of the working surface of the roller which are installed with an axial displacement, the value of which is up to two wall thicknesses of the workpiece, while the gap between the top of the profile and the mandrel of the first in the direction of the axial feed of the roller is 1.1-1.5 times greater than the value of the gap Dr. second roller. 5. The method according to claim 1, characterized in that the shape of the workpiece to obtain a non-profiled surface in the cold state is carried out by rollers, the first of which is made with an inclination angle of the generatrix of the working surface of 1.5-2.5 less than the angle of inclination of the generatrix of the subsequent rollers and offset in the axial direction relative to them by up to 0.7 of the wall thickness of the workpiece, while the gap between the top of the profile of the first roller and the mandrel exceeds the gap between the vertices of the profile of the subsequent rollers and the mandrel by 3-7%.

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